While emerging net-tools it complained that it could not find libexpat.so.0. I double checked to ensure that I had installed expat and noticed that it did not create a libexpat.so.0 symlink.
Once this symlink was created net-tools compiled fine. So the bug is either a symlink not being created or net-tools not calling on the right shared lib.
Reproducible: Didn't try
Steps to Reproduce:
1. Install new system
2. run emerge --update world
3. watch it complain on net-tools build
This was a new box I was setting up and it didn't complain on the other machine I have running. However I haven't swapped the hard drives to determine if it's having issues with net-tools
making a symlink from /usr/lib/libexpat.<version> to libexpat.so.0 fixed the problem and net-tools compiled fine.
*** This bug has been marked as a duplicate of bug 128069 ***